Flexible concrete column form panel

ABSTRACT

AN EXTENDED CIRCULAR COLUMN FORM PANEL FORMED OF FLEXIBLE SHEET MATERIAL AND ADAPTED, WHEN POSITIONED IN EDGE-TO-EDGE RELATIONSHIP WITH SIMILAR PANELS, TO FORM A CYLINDRICAL COLUMN FORM WITHIN WHICH WET CONCRETE MAY BE POURED. NOVEL RELEASABLE INTERLOCKING EDGE CONNECTIONS BETWEEN ADJACENT PANELS FACILITATE RAPID ASSEMBLY AND DISASSEMBLY OF THE PANELS UPON ONE ANOTHER BY WAY OF A TRANSVERSE SWINGING MOVEMENT.

United States Patent George F. Bowden Northbrook, Ill. 792,056

J an. 17, 1969 June 28, 197 1 Symons Mfg. Company Des Plaines, Ill.

lnventor Appl. No. Filed Patented Assignee FLEXIBLE CONCRETE COLUMN FORM PANEL 1 Chin, 8 Drawing Figs.

u.s. Cl. 249/48,

25/1 18RR, 18/43, 220/76, 249/1 19 m. c: E04g 13/02 new of Search... 249/43, 49,

ll9,l43,l27,155,l56,l60,l68,173,189,195; 25111801), 126, 128(11), 124, 130(A), 131 (A), (Silo Digest); 220/76; 18/34 (M), 43

[5 6] References Cited UNlTED STATES PATENTS 1,170,036 2/1916 Avery 220/76 2,184,265 12/1939 Winterhalter 249/119X 2,347,309 4/1944 Zoldok 220/76X 3,291,437 12/1966 Bowden et al. 249/48 Primary Examiner-J. Spenser Overholser Assistant ExaminerDe Walden W. Jones Attorney-Norman H.

Gerlach movement.

ATENTEUJUHMM 3588,02.

SHEET 1 0r 2 INVENTOR:

GEORGE F. BOWDEN Attornev PATENTEUJUN28|97| 3588027 .SHEET 2 OF 2 WIDTH IN INCHES I B y Attornev 1 FLEXIBLE CONCRETE COLUMN FORM PANEL The present invention relates generally to a flexible panel which is adapted when positioned in edge-to-edge relationship with similar panels to form a composite concrete column form within which wet concrete may be poured in connection with the formation or erection of a concrete column.

More specifically, the invention is concerned with a flexible panel of the general type which is shown and described in U.S. Pat. No. 3,291,437, granted on Dec. 13, 1966 and entitled Flexible Panel with Abutting Reaction Shoulders under Compression," the present panel being designed as an improvement on, and having certain inherent advantages over, the panel of said patent.

Briefly, the flexible concrete column form panel of the present invention is formed of a lightweight metal such, forexample, as magnesium or other material (plastic) which readily lends itself to an extrusion process in connection with panel fabrication. The side edges of the improved panel are shaped for interlocking engagement with the side edges of adjacent similar panels, one edge constituting a particular male interlock and the other edge constituting a particular counterpart female interlock. Since panels embodying the invention are both flexible and resilient, they may be joined in edge-to-edge relationship to provide a series of panels, after which the series may be bent into cylindrical configuration. If all adjacent panels of a given series are properly interlocked and then bent as aforesaid, there results a closed tubular structure which, when vertically disposed, constitutes a concrete column form suitable for reception therein of wet concrete for the erection of a cylindrical building or other column. The length of the composite tubular structure thus formed is, of course, determined by the cutoff length of the individual panels which may be initially extruded in long stock lengths. By extruding the panels so as to have widths in multiples of 1 pi inches or centimeters, any given series of selected panels will produce a concrete column having a diameter which is measured in even inches or centimeters and will thus conform to manufacturers standard specifications.

This much, at least, is common to both the panel of aforementioned US. Pat. No. 3,291,437 and the panel of the present invention, the novelty of the present invention residing in the particular panel interlock which is employed and obviates the necessity of sliding adjacent panel edges into their full interlocking relationship. More specifically, in the panel of said patent, the spline-type interlock which is provided between adjacent panels is in the form of a tongue and groove connection which is incapable of separation only by sliding the tongue of one interlock part out of the cooperating groove of the other interlock part in an endwise manner. Thus, it is necessary to bring the two interlock parts into axial alignment before assembling the same in their telescopic sliding relationship for interlocking purposes. Similarly, when separating the two interlock parts of two adjacent panels, it is necessary to slide the panels longitudinally with respect to each other to a position of end-to-end alignment and resultant disconnection of the interlock parts before the two panels can be separated from one another. This obviously requires wide displacements of the panels and much handling thereof for each assembly or disassembly operation. Furthermore, after a given set or series of panels has been subjected to one or more concrete pouring operations, the presence of hardened particles of concrete in and around the vicinity of panel junctures renders panel separation difficult and very frequently heavy and damaging impact blows are necessary to initiate the necessary longitudinal sliding action between adjacent panels. Still further, headroom considerations frequently become a factor that must be contended with as evidenced by the fact that for panels of 8 foot length, a headroom in excess of l6 feet is required especially if horizontal space limitations are such as to preclude assembly of panels on the ground or other foundation surface for subsequent gang tilting operations.

The present invention is designed to overcome the abovenoted limitations that are attendant upon the interlocking panels of the aforementioned patent and, toward this end, the invention contemplates the provision of a series of concrete column forming panels having side edge connections which establish hook-type interlocks that enable two adjacent panels to be assembled upon each other without giving consideration to their relative longitudinal position. In other words, by means of the present hook-type interlock between two adjacent panels, the panels may be interlocked in edge-to-edge fashion in substantially their final position of side-by-side assembly. By the same token, panel release or separation may be effected by simply laterally unhooking the edge connection between the two panels without requiring any longitudinal displacement of either panel with respect to the other panel. By such an arrangement, headroom considerations present no problem while the presence of hardened concrete seepage between adjacent panels has a negligible effect on the force that is required to unhook the two panels from each other.

The provision of a circular column form panelsuch as has briefly been outlined above constitutes the principal object of the present invention.

Other objects and advantages of the invention, not at this time enumerated, will readily suggest themselves as the following description ensues.

The invention consists in the several novel features which are hereinafter set forth and are more particularly defined by the claim at the conclusion hereof.

In the accompanying two sheets of drawings forming a part of this specification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a fragmentary perspective view of a concrete column form employing a series of flexible extruded panels embodying the present invention;

FIG. 2 is an enlarged end view of one of the panels of the form of FIG. I, the panel being shown in its free or unflexed condition;

FIG. 3 is a view similar to FIG. 2 except for the fact that it shows a complete, separable, two-part or sectional panel;

FIG. 4 is a horizontal sectional view taken on the horizontal plane indicated by the line 4-4 of FIG. 1 and in the direction of the arrows;

FIG. 5 is an enlarged fragmentary top edge view showing, schematically, the positioning of a pair of adjacent panels immediately prior to interlocking of the adjacent side edges thereof;

FIG. 6 is a top edge view similar to FIG. 5 but showing the two panels fully interlocked;

FIG. 7 is a sectional view similar to FIG. 5 but with one of the panels in a displaced position and illustrating the manner in which panel separation takes place during disassembly or dismantlement of the column form of FIG. 4; and

FIG. 8 is a dimension chart illustrating certain panel width considerations that are involved in connection with the invention.

Referring now to the drawings in detail, and in particular to FIGS. 1 and 4 wherein flexible extruded panels embodying the present invention are shown as constituting a concrete column form 8, there is disclosed a series of six panels, four of which are one-piece panels, while the remaining two are two-piece separable panels. The one-piece panels are designated by the reference numeral 10, one of them being shown in detail in FIG. 2, while the two-piece panels are designated by the reference numeral 12, one of the latter panels being shown in detail in FIG. 3.

As shown in FIG. 2, each panel 10 is in the form of an elongated narrow extruded sheet, preferably magnesium or a suitable plastic material, and consists of a substantially flat, although slightly transversely arched or curved, medial portion 14 which is of uniform thickness throughout and embodies enlarged, full length, laterally extending, outwardly offset hook portions 16 and 18 which extend, respectively, along its opposite side edges. The radius of the arch or curve of the medial portion M is relatively long and may be on the order of 18 inches.

The hook portion 16 of each panel 10 is not as pronounced as the hook portion 18 and it embodies a forwardly and laterally projecting interlock anchor 20 the forward surface 21 of which is of convexly curved (semicylindrical) configuration, and the rear surface of which presents a flat 22 having slight reentrant characteristics with respect to the general plane of the panel. This flat 22 merges with a reentrant surface 24 which generally tapers into the outside surface of the panel. The net result of these various curved and flat surfaces is to provide a generally rounded interlock anchor which is of flunt hook design and is designed for interlocking engagement with the hook portion 18 of the adjacent panel in any given series of panels.

The hook portion T8 of each panel 10 is a predominant one as compared to the hook portion 16 and it is more sharply defined. It embodies a forwardly and laterally extending gooseneck tongue 25 which is adapted to encompass a major portion of the interlock anchor 20 of the adjacent panel. The concave inside surface 26 of the tongue 25 is of curved (semicylindrical) design and on substantially the same curve or radius of curvature as that of the convex forward surface 21 of the interlock anchor 20, and a flat 28 opposes the flat 22 of the adjacent counterpart hook portion 16 when the two hook portions 18 and 16 are in their interlocked position as shown in FIG. 5. Thus, in the interlocked condition of the two hook portions 16 and 18, the interlock anchor 20 substantially fills the space or void in the tongue 25 so that any selected radial section through the interlocked components presents a solid column of metal with no intervening spaces or voids. By such an arrangement, seepage of concrete into the predominant hook portion 18 is effectively precluded when wet concrete is poured into the assembled column form 8.

The side edge of each panel 10 in the vicinity of the hook portion 16, exclusive of this hook portion, establishes a reaction shoulder 30 which, when the hook portions 16 and 18 of adjacent panels are fully interlocked as shown in FIG. 6, abuts against a cooperating recessed reaction shoulder 32 which is associated with, and constitutes a part of, the hook portion 18.

The specific shapes of the two hook portions 16 and 18 as described above are shapes which in actual practice have been found to afford adequate strength, ease of relative panel movement during installation and dismantling of-the concrete column form 8, and good protection against concrete seepage. Considered broadly, however, each of these hook portions possesses the essential definitive parts of any given hook structure, namely, a curved hook finger with a reentrant portion defining a concave hook void. The reentrant portions of the hook portions 16 and 18 are the two flats 22 and 28, while the hook fingers are the portions which join these flats to the side edges of each panel.

The various panels 10 are transversely flexible and somewhat resilient so that after a number of them have been assembled in interlocked edge-to-edge relationship, the assembly or series of panels may be transversely flexed as a unit to conform the inside faces thereof to the desired cylindrical contour ofthe concrete column to be formed. When so flexed, a fixed interlock takes place by reason of the fact that each two coacting reaction shoulders 30 and 32 bear hard against each other under relatively high pressure and establish a continuous smooth unbroken surface so that no vertical seam lines will be left in the hardened concrete, while at the same time each two adjacent flats 22 and 28 similarly bear against each other under pressure.

The manner in which a pair of adjacent panels in the form forming series is initially hooked together is illustrated in FIG. wherein the two panels are shown as being poised or postured at an angle of approximately 45 so that the interlock anchor 20 of the hook portion 16 of one panel may enter the void which is established by the general curvature of the gooseneck tongue 25 of the other panel 10. To effect this entry, it is necessary that the first panel be oriented so that it is disposed at an angle of at least 45 to the general plane of the second panel (disregarding the fact that both panels have a slight transverse curvature), after which the adjacent edge of the first panel may be moved in the direction of the short arrow in order to move the interlock anchor 20 into the adjacent void. Thereafter, the other or remote edge of the first panel will be swung in the direction of the long arrow so as to engage the adjacent hook portions 16 and 18 of the two panels together and effect the aforementioned engagement between the two coacting reaction shoulders 30 and 32 and the coacting flats 22 and 28. Further movement of the remote edge of the first panel will effect a forced flexing of the two panels, thus decreasing their normal radii of curvature. It will be understood that such further flexing of the panels in the assembly or a group or series of interlocked panels for column form forming purposes will be effected only after all of the panels of the linearly arranged series have been interlocked together, in which case the flexing force will be equally distributed throughout all of the panels in the series. Progressive flexing of the panels will continue until the two opposite ends of the series of panels meet each other and are fixedly secured together, at which time the series of panels will have assumed the desired cylindrical configuration.

It will be apparent that if an annular series of the panels 10 were utilized to form the concrete column form of FIG. 1, it would be difiicult, if not impossible, after hardening of the concrete within the form, to dismantle the latter. Accordingly, in order to facilitate such dismantling operation, it is contem plated that one or more of the two-part separable panels 12 will be employed in any given concrete column form. The number of separable two-part panels 12 in excess of one is a discretionary matter, but generaily speaking, where a large number of panels are employed or utilized, the use of two or more of the panels 12 will facilitate panel-handling procedures, especially where working space is at a premium and there are nearby obstructions at the scene of concrete column form erection. In the illustrated form, two of the twopart composite panels 12 are employed.

Each of the two panels 12 consists of two sections 40 and 42, the sections being provided with laterally out-turned bolting flanges 44 and 46, respectively, of appreciable width and adapted to be positioned in side-by-side abutting relationship and secured together by means of conventional nut and bolt assemblies 48 or other suitable fastening means. The section 40 has its outer side edge portion provided with a hook portion 16a which is for all intents and purposes identical with the previously described hook portion 16, while the section 42 has its outer side edge provided with a hook portion 18a which is substantially identical with the hookportion 18. In order to avoid needless repetition of description, identical reference numerals but with the suffix a have been applied to the corresponding component parts and configurations of the various hook portions as between the disclosures of FIGS. 3 and 2. The two sections 40 and 42 of each two-part panel 12 have a combined effective width equal to the width of one of the onepiece panels 10 and preferably, but not necessarily, the widths of the two sections are equal. It will be noted that when the two sections 40 and 42 are bolted together, the inside face of the panel 12 presents a smooth, substantially unbroken surface at the juncture region between panel sections in order to enhance the exterior appearance of the concrete column in the manner previously set forth in connection with the juncture regions between adjacent one-piece panels 10. The use of relatively wide bolting flanges 44 and 46 affords a good leverage when bolting these flanges together and drawing the assembled column form 8 to its true cylindrical shape. In FIG. 4, the dotted line disclosure of one of the composite two-part panels 12 illustrates the manner in which such panels facilitate dismantling of the concrete column form 8 after the poured concrete has become set. It is merely necessary to remove the various bolt assemblies 48 of either or both two-part panels 12 so that the remaining interlocked panels may be hingedly unwrapped, so to speak, from the vertical concrete column. After such unwrapping of the interlocked panels, panel separation may be readily effected by the simple expedient of swinging the panels of each adjacent pair in a direction opposite to the direction in which the panels originally were flexed until the two panels attain at least a 45 relationship, after which panel separation may easily be effected by a reversal of the panel movements shown in FIG. 5 and previously described. Alternatively, the panels may be successively removed in sequential order as illustrated in FIG. 7 and the normal bond between the inside face of a given panel relied upon to hold such panel in a fixed position while the adjacent panel is stripped forcibly from the concrete column and manipulated as shown in this view.

As is the case in connection with the various panels of aforementioned U.S. Pat. No. 3,291,437, the panels 10 and 12 are manufactured to have a width of 1 pi inches or centimeters, or roughly 3 1/7 inches when inches are employed. Such panels 10 and 12, in quantity, will suffice for use in the erection of all specified standard concrete column diameters since for each l-inch increase in the diameter of a column, an additional panel will be added to the series of panels. Thus, the concrete column form 8 of H0. 1 is designed for the erection of a 12- inch diameter concrete column. As shown in FIG. 8, a panel 110 may be constructed to have a width of 2 pi inches, or roughly 6 2/7 inches. The addition of such a panel to any given concrete column form will, of course, increase the diameter of the concrete column by 2 inches. Further multiples of pi are contemplated in the manufacture of either the panels 10 or 12, but the relatively high cost of extruding dies for such wider panels may be a deterring consideration.

It will be understood that the term panel width" as employed herein does not refer to actual end-to-end linear panel width. Rather, it refers to overall arc length of the various panels from the shoulder 30 to the shoulder 32 and excluding the forward extent of the hook portions 16 and 18.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention is particularly pointed out in the accompanying claim is the same to be limited.

lclaim:

1. A closed tubular form structure into which wet concrete is adapted to be poured in the production of a cylindrical concrete column, said structure comprising a series of normally substantially flat flexible or resilient rectangular panels disposed in edge-to-edge interlocked abutting relationship, each panel constituting an arcuate circumferential section of such structure, the side edges of each panel being provided with outwardly offset, full panel length hook portions which present reentrant hook fingers, each hook portion of each panel being interlocked with a hook portion on an adjacent panel with portions of the reentrant hook fingers thereof abutting each other in overlapping relationship, one of the hook portions of each panel embodying a forwardly and laterally projecting interlocked anchor having a convex for ward surface and a flat rear surface, the other hook portion of each panel embodying a forwardly and laterally extending gooseneek tongue having a concave inside surface conformable in curvature to the forward surface of said interlocked anchor and an inside flat surface, the concave and convex surfaces of said hook portions being of substantially semicylindrical configuration and the same radius of curvature, the gooseneck tongue of each panel encompassing the interlocked anchor of an adjacent panel and the fiat surfaces on such tongue and anchor constituting the overlapping abutting portions of said hook fingers, thepanels existing under circumferential flexion so that the overlapping portions of the hook fingers are drawn hard against each other while the adjacent side edges of the panels provide reaction shoulders that are maintained in firm abutting and sealed relationship, the reentrant extent of the hook fingers and the hook depth of the interlocked hook portions being such that panel interlock is maintained throughout all degrees of such circumferential flexion of which the panels are capable while panel interlock is released for panel separation purposes when ad acent panels are swung 

